---
title: "Pollutant vs pollution; gaseous and particulate pollutants"
subject: "Engineering Chemistry"
chapter: 3
key: "semester_2/engineering_chemistry:pollutant-vs-pollution"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/pollutant-vs-pollution
site: BCT Engineering
---

# Pollutant vs pollution; gaseous and particulate pollutants

Engineering Chemistry · Chapter 3: Environmental Chemistry

- Asked in: 2071 Magh, 1+2+2 marks
- Video: [Air Pollution](https://www.youtube.com/watch?v=_dTtvtlct9k) — Bozeman Science
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/pollutant-vs-pollution
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-3

## Question

Differentiate between pollutant and pollution. Describe the air pollution with reference to gaseous pollutant and particulate matter.

## Short answer

A pollutant is a harmful substance or agent; pollution is the undesirable environmental change it causes. Air pollution comprises gaseous pollutants like CO (binds haemoglobin), SO₂ and NOx (acid rain), and particulate matter such as dust and PM₂.₅ causing asthma and lung cancer, controlled by scrubbers, catalytic converters, and filters.

## Answer

#### Pollutant vs pollution
| Point | Pollutant | Pollution |
|---|---|---|
| Meaning | A substance or agent that harms the environment | The undesirable change in air, water or soil caused by a pollutant |
| Nature | A cause | A state/effect |
| Examples | CO, SO₂, DDT, plastic, noise | Air pollution, water pollution, soil pollution |

#### Air pollution
**Air pollution** is the presence in the air of one or more substances (gases, liquids or solids) in such quantity and for such duration that they are harmful to human beings, animals, plants, materials or the environment.

**Gaseous pollutants:** CO (incomplete combustion; binds haemoglobin), SO₂ and NOx (burning fuels; acid rain, respiratory trouble), hydrocarbons and O₃ (photochemical smog), CO₂ and CH₄ (global warming). They spread widely and are removed by absorption (scrubbers) or adsorption and by catalytic converters.

**Particulate matter:** tiny solid or liquid particles suspended in air: dust, smoke, soot, fumes, fly ash, mist, PM₁₀ and PM₂.₅. Sources: brick kilns, construction, road dust, vehicles, burning of waste and forests. They cause asthma, bronchitis, lung cancer and reduced visibility; they are controlled by electrostatic precipitators, cyclone separators, bag filters and water sprays.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which statement is correct?
   A. Pollution is the substance; pollutant is the state
   B. They mean exactly the same
   C. Pollutants are always natural
   D. A pollutant is the cause (substance/agent); pollution is the resulting undesirable change
   Answer: D. Pollutant = cause, pollution = state/effect. (Key point: Pollutant vs pollution)

2. Air pollution means
   A. Substances in air in such quantity and duration that they harm humans, animals, plants, materials or environment
   B. Any gas present in air
   C. Only smoke
   D. Only noise
   Answer: A. Harmful quantity and duration define air pollution. (Key point: Air pollution)

3. Gaseous pollutants are removed by
   A. Cyclone separators and bag filters
   B. Absorption (scrubbers), adsorption and catalytic converters
   C. Electrostatic precipitators only
   D. Trickling filters
   Answer: B. Particulates use precipitators, cyclones and bag filters. (Key point: Gaseous control)

4. Particulate matter (PM10, PM2.5) causes
   A. Anaemia only
   B. Rickets
   C. Asthma, bronchitis, lung cancer and reduced visibility
   D. Skin colour change only
   Answer: C. Fine particles reach the lungs causing respiratory disease. (Key point: Particulates)

## Related in Engineering Chemistry

- [Air pollution, pollutants, sources and remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollution-sources-remedies) — Engineering Chemistry, chapter 3
- [Water pollution, pollutants and adverse effects](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollutants-effects) — Engineering Chemistry, chapter 3
- [Air pollutants: effects and remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollutants-effects) — Engineering Chemistry, chapter 3
- [Classification of air pollutants; sources, effects](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollutants-classified) — Engineering Chemistry, chapter 3
- [Soil pollutants, effects and remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Asoil-pollutants-effects-remedies) — Engineering Chemistry, chapter 3, asked 5×
- [Water pollutants, sources; oxides making water acidic](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awater-pollutants-acidic) — Engineering Chemistry, chapter 3

## Related in other subjects

- [Particulate pollutants: sources and effects](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aparticulate-pollutants-sources-effects) — Environment and Pollution Control, chapter 1
- [Classification and sources of air pollutants](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aair-pollutants-classification-sources) — Environment and Pollution Control, chapter 1
- [Indoor air pollutants and their sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aindoor-air-pollutants-sources) — Environment and Pollution Control, chapter 3
- [Health impacts of indoor air pollutants](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aindoor-air-pollutants-health) — Energy Environment and Society, chapter 4